While submitting your app to the Windows Store, you can declare your app as accessible.
Declaring your app as accessible makes it easier to discover for users who are interested in accessible apps, such as users who have visual impairments. Users discover accessible apps by using the Accessible filter while searching the Windows Store. Declaring your app as accessible also adds the Accessible tag to your app’s description.

By declaring your app as accessible, you state that it meets the basic accessibility requirements that users need for primary scenarios using one or more of the following:

the keyboard

a high contrast theme

a variable dots per inch (dpi) setting

assistive technology such as the Microsoft Windows accessibility features, including Narrator, Magnifier, and the On-Screen Keyboard.

You should declare your app as accessible if you built and tested it for accessibility. This means that you did the following:

Set all the relevant accessibility information for UI elements, including name, role, value, status, and so on.

Implemented full keyboard accessibility, enabling the user to:

Accomplish all app scenarios by using only the keyboard.

Tab among UI elements in a logical order.

Navigate among UI elements within a control by using the arrow keys.

Use keyboard shortcuts to reach primary app functionality.

Ensured that your app UI is visually accessible: has a minimum text contrast ratio of 4.5:1, does not rely on color alone to convey information, and so on.